#include <iostream>

using namespace std;

int main() {
    int m, n;
    cin >> m >> n;
    if (n > m) {
        int tmp = n;
        n = m;
        m = tmp;
    }
    double p = 1;
    for (int i = 1; i <= m - n; i++) {
        p *= double(i + n) / double(i);
    }
    cout << (long long)(p) << endl;
    return 0;
}
